University of Mumbai 2007-7th Sem B.E Electrical and Electronics Engineering HVDC Transmission - Question Paper

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Con/5054-07.    {REVISED COURSE)    CD-7083    

(3 Hours )    [ Total Marks : 1

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N.B. : (1) Question No. 1 is compulsory.    rv

(2) Attempt any four questions out of remaining six questions.

1.    (a) Write down comparison of AC and DC Transmission.    10 (b) Explain Single Commutation failure and Double Commutation failure. 10

2.    (a) Explain the firing schemes of HVDC valves.    10 (b) Explain the problems associated with weak AC systems. What are the methods 10

to overcome them ?

3.    (a) What are the causes and effects of faults occurring in a converter station ? 10 (b) Explain the Hierarchical Control structure for a d.c. link.    10

4.    (a) What are the classification of HVDC links ? Describe each one with neat 10

diagrams.

(b) Describe with waveforms the transfer of current to the bypass valve -    10

(i)    Rectifier operation

(ii)    Inverter operation.

5.    (a) Explain with neat diagrams and waveforms the principle of 12 pulse converter. 10 (b) Explain in brief the starting and stopping of a DC link.    10

6.    (a) Explain with neat diagrams the components of HVDC Transmission system. 10 (b) Explain the influence of AC system strength on AC/DC system interaction. 10

7.    (a) Explain the causes of Harmonic generation in HVDC and its effect on the system. 10

Describe different filters used to eliminate these harmonics.

<b) Write short notes on :    10

(i) Mode Stabilization (Ii) Recent Trends in HVDC.

Attachment: university-of-mumbai-2007-b-e-electrical-and-electronics-engineering-51214-1.pdf

Earning:   Approval pending.